Is procrastination a function of poor time management?

NO. It isn’t true.

Time management problems play a part in procrastination, but the chief culprit is a lack of self-knowledge, just as time management is a function of self-knowledge.If we knew ourselves better we could create firm goals and priorities and act on them.

We would be able to say “No” to things that stopped us from achieving our goals and we would reduce procrastination.
The top theorists, although they disagree on the causes, believe it is inherently natural. All humans have suffered the consequences of this time thief.

That doesn’t help either except to give us another out.

It can become a significant enough problem to handicap one’s progress personally, academically and professionally.
Recent studies indicate that between 84 and 87 per cent of people procrastinate (the other people just haven’t gotten around to reporting it.)
Even in small doses, procrastination can lead to feelings of guilt, anxiety, dissatisfaction, depression, and self-loathing.

These feelings increase proportionally according to how long we delay the task and they are damaging to our self-esteem and sense of peace. But wanting to eliminate procrastination is not enough. We require self-knowledge.

Procrastination is a huge obstacle standing between us and the lives we want to live.

The key is knowing the life you want to live: that is having self-knowledge.

Until and unless you know who you are and what you want, the problem will persist.
If you have something important to you hanging over your head, you cannot really enjoy anything.

But you must know what IS important to you.

Most people don’t.

Here’s a good article from the Washing Post by Ana Swanson on the topic.